This depends on its users, we can't blame bitcoin due used for illegal activities such as criminals, purchase drugs, terrorists and others. better to punish the culprit is not the means of payment bitcoin.
Yes true, illegal transactions already exists although many ways done to prevent it, such as blocking the bank account. We do not blame the presence of the bitcoin as triggers illegal transactions because it depends of the user.
Bitcoin currency just isn't authorized by reason of premature and uncontrollable, so naturally many people consider bitcoin transaction means a crime is illegal. But on the other hand great country will not close bitcoin, they understand the future potential of bitcoin could control the world. If bitcoin when used for terrorist transactions was only natural because there is no governing trade via bitcoin.